Organometallic Compound, Organic Light-Emitting Device Including the Same, and Electronic Apparatus Including the Organic Light-Emitting Device

This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0120955, filed on Sep. 5, 2024, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is incorporated by reference herein in its entirety.

The disclosure relates to an organometallic compound, an organic light-emitting device including the organometallic compound, and an electronic apparatus including the organic light-emitting device.

Organic light-emitting devices (OLEDs) are self-emissive devices that have excellent characteristics in terms of viewing angles, response time, brightness, driving voltage, response speed, and the like. In addition, OLEDs can produce full-color images.

A typical organic light-emitting device includes an anode, a cathode, and an organic layer that is disposed between the anode and the cathode, and including an emission layer. A hole transport region may be disposed between the anode and the emission layer, and an electron transport region may be disposed between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. When the excitons transition from an excited state to a ground state, light is emitted.

Provided are an organometallic compound, an organic light-emitting device including the organometallic compound, and an electronic apparatus including the organic light-emitting device.

Additional aspects will be set forth in part in the detailed description that follows and, in part, will be apparent from the detailed description, or may be learned by practice of the presented exemplary embodiments herein.

According to an aspect, provided is an organometallic compound represented by Formula 1:

1 Mis a transition metal, n1 Lis a ligand represented by Formula 1A, n2 Lis a ligand represented by Formula 1B, and n1 and n2 are each independently 1 or 2, wherein, in Formula 1,

1 2 3 4 Xis C or N, Xis C or N, Xis C or N, and Xis C or N, 1 2 5 30 1 30 ring CYand ring CYare each independently a C-Ccarbocyclic group or a C-Cheterocyclic group, 4 ring CYis a 6-membered carbocyclic group or a 6-membered heterocyclic group, 1 51 52 53 Yis O, S, Se, N(R), or C(R)(R), 1 2 5 30 1 30 Arand Arare each independently a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group, a1 and a2 are each independently an integer from 1 to 3, 1 54 55 56 Lis O, S, Se, N(R), or C(R)(R), m1 is an integer from 1 to 3, 1 4 40 51 56 5 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 1 2 3 1 2 3 4 5 6 7 8 9 8 9 Rto R, R, and Rto Rare each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C-Calkyl group, a substituted or unsubstituted C-Calkenyl group, a substituted or unsubstituted C-Calkynyl group, a substituted or unsubstituted C-Calkoxy group, a substituted or unsubstituted C-Calkylthio group, a substituted or unsubstituted C-Ccycloalkyl group, a substituted or unsubstituted C-Cheterocycloalkyl group, a substituted or unsubstituted C-Ccycloalkenyl group, a substituted or unsubstituted C-Cheterocycloalkenyl group, a substituted or unsubstituted C-Caryl group, a substituted or unsubstituted C-Calkyl aryl group, a substituted or unsubstituted C-Caryl alkyl group, a substituted or unsubstituted C-Caryloxy group, a substituted or unsubstituted C-Carylthio group, a substituted or unsubstituted C-Cheteroaryl group, a substituted or unsubstituted C-Calkyl heteroaryl group, a substituted or unsubstituted C-Cheteroaryl alkyl group, a substituted or unsubstituted C-Cheteroaryloxy group, a substituted or unsubstituted C-Cheteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q), 1 5 30 1 30 neighboring two or more of a plurality of Rare optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group, 2 5 30 1 30 neighboring two or more of a plurality of Rare optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group, 3 5 30 1 30 neighboring two or more of a plurality of Rare optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group, 1 5 30 1 30 neighboring two or more of a plurality of Rare optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group, b1, b2, and b40 are each independently an integer from 1 to 10, b3 is an integer from 1 to 3, b4 is 1 or 2, 1 * and *′ each indicate a binding site to M, 5 30 1 30 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 at least one substituent of the substituted C-Ccarbocyclic group, the substituted C-Cheterocyclic group, the substituted C-Calkyl group, the substituted C-Calkenyl group, the substituted C-Calkynyl group, the substituted C-Calkoxy group, the substituted C-Calkylthio group, the substituted C-Ccycloalkyl group, the substituted C-Cheterocycloalkyl group, the substituted C-Ccycloalkenyl group, the substituted C-Cheterocycloalkenyl group, the substituted C-Caryl group, the substituted C-Calkyl aryl group, the substituted C-Caryl alkyl group, the substituted C-Caryloxy group, the substituted C-Carylthio group, the substituted C-Cheteroaryl group, the substituted C-Calkyl heteroaryl group, the substituted C-Cheteroaryl alkyl group, the substituted C-Cheteroaryloxy group, the substituted C-Cheteroarylthio group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group are each independently: 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 1 60 2 60 2 60 1 60 1 60 5 3 2 2 3 2 2 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 11 12 13 11 12 13 14 15 16 17 18 19 18 19 deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof, 3 10 1 10 3 10 1 10 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, 3 10 1 10 3 10 1 10 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 21 22 23 21 22 23 24 25 26 27 28 29 28 29 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryl alkyl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryl alkyl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof, or 31 32 33 31 32 33 34 35 36 37 38 39 38 39 —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q), and 1 9 11 19 21 29 31 39 5 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 Qto Q, Qto Q, Qto Q, and Qto Qare each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C-Calkyl group, a substituted or unsubstituted C-Calkenyl group, a substituted or unsubstituted C-Calkynyl group, a substituted or unsubstituted C-Calkoxy group, a substituted or unsubstituted C-Calkylthio group, a substituted or unsubstituted C-Ccycloalkyl group, a substituted or unsubstituted C-Cheterocycloalkyl group, a substituted or unsubstituted C-Ccycloalkenyl group, a substituted or unsubstituted C-Cheterocycloalkenyl group, a substituted or unsubstituted C-Caryl group, a substituted or unsubstituted C-Calkyl aryl group, a substituted or unsubstituted C-Caryl alkyl group, a substituted or unsubstituted C-Caryloxy group, a substituted or unsubstituted C-Carylthio group, a substituted or unsubstituted C-Cheteroaryl group, a substituted or unsubstituted C-Calkyl heteroaryl group, a substituted or unsubstituted C-Cheteroaryl alkyl group, a substituted or unsubstituted C-Cheteroaryloxy group, a substituted or unsubstituted C-Cheteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group. wherein, in Formulae 1A and 1B,

Another aspect provides an organic light-emitting device including a first electrode; a second electrode; and an organic layer arranged between the first electrode and the second electrode, wherein the organic layer comprises an emission layer, and wherein the organic layer further comprises at least one organometallic compound represented by Formula 1.

Still another aspect provides an electronic apparatus comprising the organic light-emitting device.

Reference will now be made in further detail to exemplary embodiments, examples of which are illustrated in the accompanying drawing, wherein like reference numerals refer to like elements throughout the specification. In this regard, the present embodiments may have different forms and should not be construed as being limited to the detailed descriptions set forth herein. Accordingly, the embodiments are merely described in further detail below, and by referring to the FIGURE, to explain certain aspects and features. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

The terminology used herein is for the purpose of describing one or more exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “or” means “and/or.” It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present embodiments.

Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.

It will be understood that when an element is referred to as being “on” another element, it can be directly in contact with the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this general inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

An organometallic compound according to an aspect is represented by Formula 1: Formula 1

1 wherein Min Formula 1 is a transition metal.

1 For example, Mmay be a first-row transition metal of the Periodic Table of Elements, a second-row transition metal of the Periodic Table of Elements, or a third-row transition metal of the Periodic Table of Elements.

1 In one or more embodiments, Mmay be iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), or rhodium (Rh).

1 In one or more embodiments, Mmay be Ir, Pt, Os, or Rh.

1 In one or more embodiments, Mmay be Ir.

In Formula 1, n1 is 1 or 2, and n2 is 1 or 2.

In one or more embodiments, a sum of n1 and n2 may be 2 or 3.

1 In one or more embodiments, Mmay be Ir, and the sum of n1 and n2 may be 3.

1 In one or more embodiments, Mmay be Pt, and the sum of n1 and n2 may be 2.

n1 Lin Formula 1 is a ligand represented by Formula 1A:

1 2 In Formula 1A, Xis C or N, and Xis C or N.

1 2 In one or more embodiments, Xmay be N, and Xmay be C.

1 2 5 30 1 30 Ring CYand ring CYin Formula 1A are each independently a C-Ccarbocyclic group or a C-Cheterocyclic group.

1 2 the first ring may be a cyclopentane group, a cyclopentadiene group, a furan group, a thiophene group, a pyrrole group, a silole group, an indene group, a benzofuran group, a benzothiophene group, an indole group, a benzosilole group, an oxazole group, an isoxazole group, an oxadiazole group, an isoxadiazole group, an oxatriazole group, an isoxatriazole group, a thiazole group, an isothiazole group, a thiadiazole group, an isothiadiazole group, a thiatriazole group, an isothiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, an azasilole group, a diazasilole group, or a triazasilole group, and the second ring may be an adamantane group, a norbornane group, a norbornene group, a cyclohexane group, a cyclohexene group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group. In one or more embodiments, ring CYand ring CYmay each independently be i) a first ring, ii) a second ring, iii) a condensed ring group in which at least two first rings are condensed with each other, iv) a condensed ring group in which at least two second rings are condensed with each other, or v) a condensed ring group in which at least one first ring is condensed with at least one second ring,

1 2 In one or more embodiments, ring CYand ring CYmay each independently be a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a phenanthrene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a benzofuran group, a benzothiophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group.

1 In one or more embodiments, ring CYmay each independently be a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, or a quinazoline group.

2 In one or more embodiments, ring CYmay be a benzene group or a naphthalene group.

In one or more embodiments, a moiety represented by

in Formula 1A may be a group represented by one of Formulae CY(1)-1 to CY(1)-16:

11 14 1 11 14 Rto Rare each independently as described in connection with R, provided that Rto Rmay not be hydrogen, 1 * indicates a binding site to M, and *″ indicates a binding site to a neighboring atom. In Formulae CY(1)-1 to CY(1)-16,

11 14 1 10 3 2 3 1 10 3 2 2 1 2 3 1 2 3 For example, each of Rto Rin Formulae CY(1)-1 to CY(1)-16 may independently be deuterium, a C-Calkyl group (for example, —CH, —CHCH, or the like), a C-Calkyl group substituted with at least one deuterium (for example, —CD, —CDH, —CDH, or the like), —Si(Q)(Q)(Q), or —Ge(Q)(Q)(Q).

In one or more embodiments, a moiety represented by

in Formula 1A may be a group represented by one of Formulae CY(2)-1 to CY(2)-16:

21 24 2 21 24 Rto Rare each independently as described in connection with R, provided that none of Rto Rmay be hydrogen, 1 *′ indicates a binding site to M, and *″ indicates a binding site to a neighboring atom. In Formulae CY(2)-1 to CY(2)-16,

11 14 1 1 3 2 3 For example, Rto Rin Formula CY(1)-1 to CY(1)-16 may be deuterium, or a C-Calkyl group (for example, —CH, —CHCH, or the like).

n1 In one or more embodiments, Lmay be a ligand represented by Formula 1A-1:

11 11 12 12 13 13 14 14 Xmay be C(R) or N, Xmay be C(R) or N, Xmay be C(R) or N, and Xmay be C(R) or N, 21 21 22 22 23 23 24 24 Xmay be C(R) or N, Xmay be C(R) or N, Xmay be C(R) or N, and Xmay be C(R) or N, 11 14 1 Rto Rare each independently as described in connection with R, and 21 24 2 Rto Rare each independently as described in connection with R. In Formula 1A-1,

n2 Lin Formula 1 is a ligand represented by Formula 1B:

3 4 In Formula 1B, Xis C or N, and Xis C or N.

3 4 In one or more embodiments, Xmay be N, and Xmay be C.

4 Ring CYin Formula 1B is a 6-membered carbocyclic group or a 6-membered heterocyclic group.

4 In one or more embodiments, ring CYmay be a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.

1 51 52 53 Yin Formula 1B is O, S, Se, N(R), or C(R)(R).

1 2 5 30 1 30 Arand Arin Formula 1B are each independently a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group.

1 2 5 10 1 10 5 10 1 10 6 60 1 60 In one or more embodiments, Arand Armay each independently be a substituted or unsubstituted C-Ccycloalkyl group, a substituted or unsubstituted C-Cheterocycloalkyl group, a substituted or unsubstituted C-Ccycloalkenyl group, a substituted or unsubstituted C-Cheterocycloalkenyl group, a substituted or unsubstituted C-Caryl group, a substituted or unsubstituted C-Cheteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

a1 and a2 in Formula 1B are each independently an integer from 1 to 3.

1 2 In Formula 1B, when a1 is 2 or greater, Arin the number of a1 may be identical to or different from each other, and when a2 is 2 or greater, Arin the number of a2 may be identical to or different from each other.

1 2 5 10 1 1 6 60 1 60 In one or more embodiments, Arand Armay each independently be a substituted or unsubstituted C-Ccycloalkenyl group, a substituted or unsubstituted C-Ca heterocycloalkenyl group, a substituted or unsubstituted C-Caryl group, or a substituted or unsubstituted C-Cheteroaryl group,

In some embodiments, a1 and a2 may each be 1.

1 54 55 56 Lin Formula 1B is O, S, Se, N(R), or C(R)(R).

m1 in Formula 1B is an integer from 1 to 3.

1 When m1 in Formula 1B is 2 or greater, each Lin the number of m1 may be identical to or different from each other.

1 In one or more embodiments, Lmay be O, S, or Se, and m1 may be 1.

1 1 2 In one or more embodiments, a ring including Ar, L, and Arin Formula 1B may be an octagonal ring.

n2 In one or more embodiments, Lmay be a ligand represented by one of Formulae 1B(1)-1 to 1B(1)-3:

3 4 4 1 1 2 1 3 4 X, X, ring CY, Y, Ar, Ar, a1, a2, L, m1 R, b3, R, and b4 are each as described herein, and 5 6 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 Rand Rmay each independently be deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group; 1 60 2 60 2 60 1 60 1 60 5 3 2 2 3 2 2 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 11 12 13 11 12 13 14 15 16 17 18 19 18 19 a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof; 3 10 1 10 3 10 1 10 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group; 3 10 1 10 3 10 1 10 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 21 22 23 21 22 23 24 25 26 27 28 29 28 29 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryl alkyl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryl alkyl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof; or 31 32 33 31 32 33 34 35 36 37 38 39 38 39 —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q), 11 19 21 29 31 39 Qto Q, Qto Q, and Qto Qare as described herein, b5 and b6 may each independently be an integer from 1 to 4, and 1 * and *′ each indicate a binding site to M. In Formulae 1B(1)-1 to 1B(1)-3,

n2 In one or more embodiments, Lmay be a ligand represented by one of Formulae 1B(2)-1 to 1B(2)-6:

3 4 1 1 2 1 3 4 X, X, Y, Ar, Ar, a1, a2, L, m1, R, b3, R, and b4 are each as described herein, 41 41 42 42 43 43 44 44 Xmay be C(R) or N, Xmay be C(R) or N, Xmay be C(R) or N, and Xmay be C(R) or N, 41 44 40 Rto Rare each independently as described in connection with R, and 1 * and *′ each indicate a binding site to M. In Formulae 1B(1)-1 to 1B(2)-6,

n2 In one or more embodiments, Lmay be a ligand represented by one of Formulae 1B-1 to 1B-12:

3 4 1 1 2 1 3 4 40 X, X, Y, Ar, Ar, a1, a2, L, R, b3, R, b4, and Rare each as described herein, 5 6 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 Rand Rmay each independently be deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group; 1 60 2 60 2 60 1 60 1 60 5 3 2 2 3 2 2 3 10 1 1 3 10 1 10 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 11 12 13 11 12 13 14 15 16 17 18 19 18 19 a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), -Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof; 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group; 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 3 10 1 1 3 10 1 1 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 21 22 23 21 22 23 24 25 26 27 28 29 28 29 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryl alkyl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryl alkyl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof; or 31 32 33 31 32 33 34 35 36 37 38 39 38 39 —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q), and 11 19 21 29 31 39 Qto Q, Qto Q, and Qto Qare each as described herein, b5 and b6 may each independently be an integer from 1 to 4, b40 may be an integer from 1 to 4, and 1 * and *′ each indicate a binding site to M. In Formulae 1B-1 to 1B-12,

1 4 40 51 56 5 1 60 2 60 2 60 1 60 1 60 3 1 1 1 3 1 1 1 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 1 2 3 1 2 3 4 5 6 7 8 9 8 9 Rto R, R, and Rto Rin Formulae 1A and 1B are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C-Calkyl group, a substituted or unsubstituted C-Calkenyl group, a substituted or unsubstituted C-Calkynyl group, a substituted or unsubstituted C-Calkoxy group, a substituted or unsubstituted C-Calkylthio group, a substituted or unsubstituted C-Ccycloalkyl group, a substituted or unsubstituted C-Cheterocycloalkyl group, a substituted or unsubstituted C-Ccycloalkenyl group, a substituted or unsubstituted C-Cheterocycloalkenyl group, a substituted or unsubstituted C-Caryl group, a substituted or unsubstituted C-Calkyl aryl group, a substituted or unsubstituted C-Caryl alkyl group, a substituted or unsubstituted C-Caryloxy group, a substituted or unsubstituted C-Carylthio group, a substituted or unsubstituted C-Cheteroaryl group, a substituted or unsubstituted C-Calkyl heteroaryl group, a substituted or unsubstituted C-Cheteroaryl alkyl group, a substituted or unsubstituted C-Cheteroaryloxy group, a substituted or unsubstituted C-Cheteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q).

1 4 40 51 56 5 3 2 2 3 2 2 1 20 1 20 1 20 hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkoxy group, or a C-Calkylthio group; 1 20 1 20 1 20 5 3 2 2 3 2 2 1 10 a C-Calkyl group, a C-Calkoxy group, or a C-Calkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or a combination thereof; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, or an imidazopyrimidinyl group; 5 3 2 2 3 2 2 1 20 1 20 1 20 a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, or an imidazopyrimidinyl group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkoxy group, a C-Calkylthio group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or a combination thereof; or 1 2 3 1 2 3 4 5 6 7 8 9 8 9 —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q), and 1 9 Qto Qmay each independently be: 3 3 2 2 2 3 2 3 2 2 2 2 3 2 2 3 2 3 2 2 2 2 —CH, —CD, —CDH, —CDH, —CHCH, —CHCD, —CHCDH, —CHCDH, —CHDCH, —CHDCDH, —CHDCDH, —CHDCD, —CDCD, —CDCDH, or —CDCDH; an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, or a naphthyl group; or 1 10 an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, or a naphthyl group, each substituted with deuterium, a C-Calkyl group, a phenyl group, or a combination thereof. In one or more embodiments, Rto R, R, and Rto Rmay each independently be:

1 4 40 51 56 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group; a group represented by one of Formulae 9-1 to 9-39, 9-44 to 9-61, 9-201 to 9-240, 10-1 to 10-129, or 10-201 to 10-350; or 1 2 3 1 2 3 4 5 —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), or —N(Q)(Q). In one or more embodiments, Rto R, R, and Rto Rmay each independently be:

In Formulae 9-1 to 9-39, 9-44 to 9-61, 9-201 to 9-240, 10-1 to 10-129, and 10-201 to 10-350, * indicates a binding site to a neighboring atom, “Ph” is a phenyl group, “TMS” is a trimethylsilyl group, and “TMG” is a trimethylgermyl group.

1 2 5 3 2 2 3 2 2 1 20 hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, -CFH, a cyano group, or a C-Calkyl group; 1 20 5 3 2 2 3 2 2 1 20 a C-Calkyl group, substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a cyano group, C-Calkyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or a combination thereof; a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a fluorenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, or a triazinyl group; 5 3 2 2 3 2 2 1 20 a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a fluorenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, or a triazinyl group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a cyano group, a C-Calkyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or a combination thereof; or 1 2 3 1 2 3 —Si(Q)(Q)(Q) or —Ge(Q)(Q)(Q), and 1 Qto Q may each independently be: 3 3 2 2 2 3 2 3 2 2 2 2 3 2 2 3 2 3 2 2 2 2 —CH, —CD, —CDH, —CDH, —CHCH, —CHCD, —CHCDH, —CHCDH, —CHDCH, —CHDCDH, —CHDCDH, —CHDCD, —CDCD, —CDCDH, or —CDCDH; an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, or a naphthyl group; or 1 10 an n-propyl group, an iso-propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, or a naphthyl group, each substituted with deuterium, a C-Calkyl group, a phenyl group, or a combination thereof; and 3 4 40 51 56 R, R, R, and Rto Rmay each independently be: 5 3 2 2 3 2 2 1 20 hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a cyano group, or a C-Calkyl group; 1 20 5 3 2 2 3 2 2 1 20 a C-Calkyl group, substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a cyano group, C-Calkyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or a combination thereof; a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a fluorenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, or a triazinyl group; or 5 3 2 2 3 2 2 1 20 a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a fluorenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, or a triazinyl group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a cyano group, a C-Calkyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or a combination thereof. In one or more embodiments, Rand Rmay each independently be:

1 5 30 1 30 Neighboring two or more of a plurality of Rin Formula 1A are optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group.

2 5 30 1 30 Neighboring two or more of a plurality of Rin Formula 1A are optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group.

3 5 30 1 30 Neighboring two or more of a plurality of Rin Formula 1B are optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group.

40 5 30 1 30 Neighboring two or more of a plurality of Rare optionally bonded to each other to form a substituted or unsubstituted C-Ccarbocyclic group or a substituted or unsubstituted C-Cheterocyclic group,

b1, b2, and b40 in Formulae 1A and 1B are each independently an integer from 1 to 10.

b3 in Formula 1B is an integer from 1 to 3.

b4 in Formula 1B is 1 or 2.

1 * and *′ in Formulae 1A and 1B each indicate a binding site to M.

In one or more embodiments, the organometallic compound represented by Formula 1 may be one of Compounds 1 to 77:

In one or more embodiments, the organometallic compound represented by Formula 1 may be electrically neutral.

The organometallic compound represented by Formula 1 satisfies the structure of Formula 1 and includes a ligand having a structure represented by Formula 1B. Due to this structure, the organometallic compound represented by Formula 1 has excellent luminescence characteristics, and has such characteristics suitable for use as a luminescent material with high color purity by controlling the emission wavelength range.

In addition, the organometallic compound represented by Formula 1 has excellent electrical mobility, and thus an electronic device including at least one of the organometallic compounds represented by Formula 1, for example, an organic light-emitting device, may exhibit a low driving voltage, a high efficiency, a low roll-off ratio, and/or a long lifespan.

In one or more embodiments, the maximum emission wavelength (emission peak wavelength maximum, Amax) of the emission spectrum or electroluminescence spectrum of the organometallic compound represented by Formula 1 may be about 490 nanometers (nm) to about 550 nm.

Synthesis methods of the organometallic compound represented by Formula 1 may be recognizable by one of ordinary skill in the art and by referring to Synthesis Examples provided below.

The organometallic compound represented by Formula 1 is suitable for use in an organic layer of an organic light-emitting device, for example, for use as a dopant in an emission layer of the organic layer. Thus, according to one or more embodiments, an organic light-emitting device includes a first electrode; a second electrode; and an organic layer that is disposed or arranged between the first electrode and the second electrode, wherein the organic layer includes an emission layer, and wherein the organic layer further includes at least one organometallic compound represented by Formula 1.

The organic light-emitting device may have an excellent driving voltage, excellent maximum external quantum efficiency, and/or excellent lifespan characteristics by including an organic layer including at least one of the organometallic compounds represented by Formula 1 as described herein.

The organometallic compound represented by Formula 1 may be used between a pair of electrodes of an organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this regard, the organometallic compound may serve as a dopant, and the emission layer may further include a host. When the emission layer further includes a host, the amount of the host in the emission layer may be greater than an amount of the at least one organometallic compound represented by Formula 1, on a weight basis.

In one or more embodiments, the emission layer may emit a green light. For example, the emission layer may emit a green light having a maximum emission wavelength of about 490 nm to about 550 nm.

The expression “(an organic layer) includes at least one organometallic compound represented by Formula 1” as used herein may be interpreted as “(an organic layer) may include one organometallic compound of Formula 1 or at least two different organometallic compounds of Formula 1.”

For example, the organic layer may include, as the at least one organometallic compound represented by Formula 1, only Compound 1. In this regard, Compound 1 may be included in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the at least one organometallic compound represented by Formula 1, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may exist in the same layer (for example, both Compound 1 and Compound 2 may exist in the emission layer).

The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode, or the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.

For example, in the organic light-emitting device, the first electrode may be an anode, and the second electrode may be a cathode, and the organic layer may further include a hole transport region arranged between the first electrode and the emission layer; and an electron transport region arranged between the emission layer and the second electrode, and the hole transport region may include a hole injection layer, a hole transport layer, an electron-blocking layer, a buffer layer, or a combination thereof, and the electron transport region may include a hole-blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

The term “organic layer” as used herein refers to a single layer and/or a plurality of layers that are located between the first electrode and the second electrode of the organic light-emitting device. The “organic layer” may include, in addition to an organic compound, an organometallic complex including a metal.

10 10 10 11 15 19 The FIGURE is a schematic cross-sectional view of an organic light-emitting deviceaccording to one or more embodiments. Hereinafter, the structure and manufacturing method of the organic light-emitting deviceaccording to one or more embodiments will be described with reference to the FIGURE, but embodiments are not limited thereto. The organic light-emitting devicemay have a structure in which a first electrode, an organic layer, and a second electrodeare sequentially stacked in the stated order.

11 19 A substrate may be further disposed under the first electrodeor on the second electrode. The substrate may be a substrate commonly used in organic light-emitting devices, e.g., a glass substrate or a transparent plastic substrate, which have excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water repellency.

11 11 11 11 11 11 11 2 The first electrodemay be formed by, for example, depositing or sputtering, onto the substrate, a material for forming the first electrode. The first electrodemay be an anode. The material for forming the first electrodemay be selected from materials with a high work function for easy hole injection. The first electrodemay be a reflective electrode, a transflective electrode, or a transmissive electrode. The material for forming the first electrodemay be indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO), or zinc oxide (ZnO). In one or more embodiments, the material for forming the first electrodemay be a metal, such as magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

11 11 11 The first electrodemay have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrodemay have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrodeis not limited thereto.

15 11 The organic layermay be disposed on the first electrode.

15 The organic layermay include a hole transport region, an emission layer, and an electron transport region.

11 The hole transport region may be disposed between the first electrodeand the emission layer.

The hole transport region may include a hole injection layer, a hole transport layer, an electron-blocking layer, a buffer layer, or a combination thereof.

11 The hole transport region may include only either a hole injection layer or a hole transport layer. In one or more embodiments, the hole transport region may have a hole injection layer/hole transport layer structure or a hole injection layer/hole transport layer/electron-blocking layer structure, in which respective layers of each structure are sequentially stacked in the stated order from the first electrode.

11 When the hole transport region includes an hole injection layer, the hole injection layer may be formed on the first electrodeby using various methods, for example, vacuum deposition, spin coating, casting, and/or Langmuir-Blodgett (LB) deposition, but embodiments are not limited thereto.

−8 −3 When the hole injection layer is formed by a vacuum deposition method, deposition conditions may vary depending on a compound used as a material for forming the hole injection layer, a structure and thermal characteristics of the desired hole injection layer, or the like. For example, a deposition temperature may be about 100° C. to about 500° C., a vacuum degree may be about 10torr to about 10torr, and a deposition rate may be about 0.01 angstroms per second (Å/sec) to about 100 Å/sec, but embodiments are not limited thereto.

When the hole injection layer is formed by a spin coating method, coating conditions may vary depending on a compound used as a material for forming the hole injection layer, a structure and thermal characteristics of the desired hole injection layer, or the like. For example, a coating rate may be about 2,000 revolutions per minute (rpm) to about 5,000 rpm, and a temperature at which heat treatment is performed to remove a solvent after coating may be about 80° C. to about 200° C., but embodiments are not limited thereto.

The conditions for forming the hole transport layer and the electron-blocking layer may be referred to the description provided for the conditions for forming the hole injection layer.

The hole transport region may include, for example, at least one of 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4′,4″-tris{N-(2-naphthyl)-N-phenylamino}-triphenylamine (2-TNATA), N,N′-di(1-naphthyl)-N,N′diphenylbenzidine (NPB), β-NPB, N,N-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD), Spiro-TPD, Spiro-NPB, methylated NPB, 4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine](TAPC), 4,4′-bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD), 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201, or a compound represented by Formula 202, but embodiments are not limited thereto:

101 102 a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, or a pentacenylene group; or 5 1 60 2 60 2 60 1 60 1 60 3 10 3 10 1 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, or a pentacenylene group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a C-Ccycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryl alkyl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryl alkyl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, or a combination thereof. wherein Arand Arin Formula 201 may each independently be:

xa and xb in Formula 201 may each independently be an integer from 0 to 5, or 0, 1, or 2. For example, xa may be 1, and xb may be 0, but xa and xb are not limited thereto.

101 108 111 119 121 124 5 1 10 1 1 1 1 hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, pentyl group, a hexyl group, or the like), a C-Calkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, or the like), or a C-Calkylthio group; 1 1 1 1 1 1 5 a C-Calkyl group, a C-Calkoxy group, or a C-Calkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, or a combination thereof; a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, or a pyrenyl group; or 5 1 1 1 1 1 1 a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, or a pyrenyl group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkoxy group, a C-Calkylthio group, or a combination thereof, but embodiments are not limited thereto. Rto R, Rto R, and Rto Rin Formulae 201 and 202 may each independently be:

109 a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinyl group; or 5 1 20 1 20 1 20 a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinyl group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkoxy group, a C-Calkylthio group, a phenyl group, a naphthyl group, an anthracenyl group, a pyridinyl group, or a combination thereof. Rin Formula 201 may be:

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A, but embodiments are not limited thereto:

101 111 112 109 wherein R, R, R, and Rin Formula 201A may each be as described herein.

For example, the compound represented by Formula 201 and the compound represented by Formula 202 may include, but are not limited to, compounds HT1 to HT20:

A thickness of the hole transport region may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one of a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be about 50 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region may further include, in addition to these materials, a charge-generation material for improving conductivity. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant. The p-dopant may be, but is not limited to, one of a quinone derivative, a metal oxide, or a cyano group-containing compound. For example, non-limiting examples of the p-dopant may be a quinone derivative, such as tetracyanoquinonedimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), 1,3,4,5,7,8-hexafluorotetracyanonaphthoquinodimethane (F6-TCNNQ), or the like; a metal oxide, such as a tungsten oxide, a molybdenum oxide, or the like; or a cyano group-containing compound, such as Compounds HT-D1 or F12, but embodiments are not limited thereto:

The hole transport region may include a buffer layer.

The buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, thus increasing efficiency.

The emission layer may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may generally be similar to those applied in forming the hole injection layer although the deposition or coating conditions may vary according to a material that is used to form the emission layer.

In some embodiments, when the hole transport region includes an electron-blocking layer, a material for forming the electron-blocking layer may be selected from, but is not limited to, the above-described materials that may be used in the hole transport region and a host material described hereinbelow. For example, when the hole transport region includes an electron-blocking layer, a material for forming the electron-blocking layer may be mCP, which will be described hereinbelow.

The emission layer may include a host and a dopant, and the dopant may include at least one of the organometallic compounds represented by Formula 1.

The host may include at least one or 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), 9,10-di(naphth-2-yl)anthracene (ADN) (also referred to as “DNA”), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl (CDBP), 1,3,5-tris(carbazol-9-yl)benzene (TCP), 1,3-bis(N-carbazolyl)benzene (mCP), Compound H50, or Compound H51, but embodiments are not limited thereto:

In one or more embodiments, the host may include a compound represented by Formula 301 below:

111 112 a phenylene group, a naphthylene group, a phenanthrenylene group, or a pyrenylene group; or a phenylene group, a naphthylene group, a phenanthrenylene group, or a pyrenylene group, each substituted with a phenyl group, a naphthyl group, an anthracenyl group, or a combination thereof. wherein Arand Arin Formula 301 may each independently be:

113 116 1 10 a C-Calkyl group which is substituted with a phenyl group, a naphthyl group, an anthracenyl group, or a combination thereof; a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, or a fluorenyl group; 5 1 60 2 60 2 60 1 60 1 60 a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, or a fluorenyl group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, or a combination thereof; or Arto Arin Formula 301 may each independently be:

but embodiments are not limited thereto.

113 116 1 10 a C-Calkyl group, a phenyl group, a naphthyl group, a phenanthrenyl group, or a pyrenyl group; or a phenyl group, a naphthyl group, a phenanthrenyl group, or a pyrenyl group, each substituted with a phenyl group, a naphthyl group, an anthracenyl group, or a combination thereof. Arto Arin Formula 301 may each independently be:

g, h, i, and j in Formula 301 may each independently be an integer from 0 to 4, and g, h, i, and j may each independently be, for example, 0, 1, or 2.

In one or more embodiments, the host may include a compound represented by Formula 302:

122 125 113 wherein Arto Arin Formula 302 are defined the same as Arin Formula 301.

126 127 1 10 Arand Arin Formula 302 may each independently be a C-Calkyl group (for example, a methyl group, an ethyl group, a propyl group, or the like).

k and l in Formula 302 may each independently be an integer from 0 to 4. For example, k and l may each independently be 0, 1, or 2.

When the organic light-emitting device is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In one or more embodiments, the emission layer may have a structure in which a red emission layer, a green emission layer, and/or a blue emission layer are stacked, and thus, various modifications such as emission of white light are possible.

When the emission layer includes a host and a dopant, the amount of the dopant may generally be about 0.01 parts by weight to about 15 parts by weight, with respect to 100 parts by weight of the host, but embodiments are not limited thereto.

The thickness of the emission layer may be about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within the range described above, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.

Next, an electron transport region may be located on or disposed on the emission layer.

The electron transport region may include a hole-blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

For example, the electron transport region may have a hole-blocking layer/electron transport layer/electron injection layer structure, or an electron transport layer/electron injection layer structure, and the structure of the electron transport region is not limited thereto. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

Conditions for forming the hole-blocking layer, the electron transport layer, and the electron injection layer which constitute the electron transport region may be referred to the description provided for the conditions for forming the hole injection layer.

When the electron transport region includes a hole-blocking layer, the hole-blocking layer may include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), or bis(2-methyl-8-quinolinolato-N1,O8)-(1,1′-biphenyl-4-olato)aluminum (BAlq), but embodiments are not limited thereto:

A thickness of the hole-blocking layer may be about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thickness of the hole-blocking layer is within these ranges, excellent hole-blocking characteristics may be obtained without a substantial increase in driving voltage.

3 The electron transport layer may further include at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), tris(8-hydroxy-quinolinato)aluminum (Alq), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1′-biphenyl-4-olato)aluminum (BAlq), 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), or 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), but embodiments are not limited thereto:

In one or more embodiments, the electron transport layer may include at least one of ET1 to ET25, but embodiments are not limited thereto:

The thickness of the electron transport layer may be about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may further include a metal-containing material, in addition to the material as described above.

The metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2, but embodiments are not limited thereto:

19 The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode.

2 The electron injection layer may include LiF, NaCl, CsF, LiO, BaO, or a combination thereof.

A thickness of the electron injection layer may be about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range as described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.

19 15 19 19 19 The second electrodemay be disposed on the organic layer. The second electrodemay be a cathode. A material for forming the second electrodemay be a metal, an alloy, an electrically conductive compound, or a combination thereof, which have a relatively low work function. For example, lithium (Li), magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag) may be used as the material for forming the second electrode. In one or more embodiments, to manufacture a top-emission type light-emitting device, various modifications, such as formation of a transmissive second electrode using ITO or IZO, is possible.

The organic light-emitting device has been described with reference to the FIGURE, but embodiments are not limited thereto.

According to one or more embodiments, a diagnostic composition includes at least one organometallic compound represented by Formula 1.

The organometallic compound represented by Formula 1 may provide high luminous efficiency, and thus, a diagnostic composition including at least one of the organometallic compounds represented by Formula 1 may have high diagnostic efficiency.

The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, a biomarker, or the like, but embodiments are not limited thereto.

1 60 1 60 1 60 The term “C-Calkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an iso-amyl group, a hexyl group, or the like. The term “C-Calkylene group” as used herein refers to a divalent group having the same structure as the C-Calkyl group.

1 60 101 101 1 60 The term “C-Calkoxy group” as used herein refers to a monovalent group represented by —OA(wherein Ais the C-Calkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, an isopropoxy group, or the like.

1 60 101 101 1 60 The term “C-Calkylthio group” as used herein refers to a monovalent group represented by —SA(wherein Ais the C-Calkyl group).

2 60 2 60 2 60 2 60 The term “C-Calkenyl group” as used herein refers to a structure containing at least one carbon-carbon double bond in the middle or at the end of the C-Calkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, a butenyl group, or the like. The term “C-Calkenylene group” as used herein refers to a divalent group having the same structure as the C-Calkenyl group.

2 60 2 60 The term “C-Calkynyl group” as used herein refers to a group containing at least one carbon-carbon triple bond in the middle or at the end of the C-Calkyl group, and non-limiting examples thereof include an ethynyl group, a propynyl group, or the like.

2 60 2 60 The term “C-Calkynylene group” as used herein refers to a divalent group having the same structure as the C-Calkynyl group.

3 10 3 10 3 10 The term “C-Ccycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon ring group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, an adamantanyl group, a norbornanyl group, or the like. The term “C-Ccycloalkylene group” as used herein refers to a divalent group having the same structure as the C-Ccycloalkyl group.

1 1 1 1 1 1 The term “C-Cheterocycloalkyl group” as used herein refers to a monovalent ring group having at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as a ring-forming atom and 1 to 10 carbon atoms as ring-forming atom(s), and non-limiting examples thereof include a tetrahydrofuranyl group, a tetrahydrothiophenyl group, or the like. The term “C-Cheterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C-Cheterocycloalkyl group.

3 10 3 10 3 10 The term “C-Ccycloalkenyl group” as used herein refers to a monovalent ring group that has 3 to 10 carbon atoms, and at least one carbon-carbon double bond in the ring thereof and has no aromaticity, and examples thereof include a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, or a norbornenyl group. The term “C-Ccycloalkenylene group” as used herein refers to a divalent group having the same structure as the C-Ccycloalkenyl group.

1 1 1 1 1 1 1 1 The term “C-Cheterocycloalkenyl group” as used herein refers to a monovalent ring group that has at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as a ring-forming atom, 1 to 10 carbon atoms as ring-forming atom(s), and at least one double bond in the ring thereof. Non-limiting examples of the C-Ca heterocycloalkenyl group include a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, or the like. The term “C-Ca heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C-Ca heterocycloalkenyl group.

6 60 6 6 6 60 6 60 6 60 The term “C-Caryl group” as used herein refers to a monovalent group having a carbocyclic aromatic ring system having 6 to 60 carbon atoms, and the term “C-Ca arylene group” as used herein refers to a divalent group having a carbocyclic aromatic ring system having 6 to 60 carbon atoms. Non-limiting examples of the C-Caryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a chrysenyl group, or the like. When the C-Caryl group and the C-Carylene group each include two or more rings, the rings may be fused with each other.

7 60 6 60 1 60 7 60 1 60 6 60 The term “C-Calkyl aryl group” as used herein refers to a C-Caryl group substituted with at least one C-Calkyl group. The term “C-Caryl alkyl group” as used herein refers to a C-Calkyl group substituted with at least one C-Caryl group.

1 60 1 60 1 60 The term “C-Cheteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic ring system having at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as a ring-forming atom and 1 to 60 carbon atoms as ring-forming atom(s). The term “C-Cheteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic ring system that contains at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as a ring-forming atom and has 1 to 60 carbon atoms as ring forming atom(s). Non-limiting examples of the C-Cheteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, or the like.

1 60 1 60 When the C-Cheteroaryl group and the C-Cheteroarylene group each include two or more rings, the rings may be fused with each other.

2 60 1 60 1 60 2 60 1 60 1 60 The term “C-Calkyl heteroaryl group” as used herein refers to a C-Cheteroaryl group substituted with at least one C-Calkyl group. The term “C-Cheteroaryl alkyl group” as used herein refers to a C-Calkyl group substituted with at least one C-Cheteroaryl group.

6 60 102 102 6 60 6 60 103 103 6 60 The term “C-Caryloxy group” as used herein refers to —OA(wherein Ais the C-Caryl group), and the term “C-Carylthio group” as used herein refers to —SA(wherein Ais the C-Caryl group).

1 60 104 104 1 60 1 60 105 105 1 60 The term “C-Cheteroaryloxy group” as used herein indicates —OA(wherein Ais the C-Cheteroaryl group), and the term “C-Cheteroarylthio group” as used herein indicates —SA(wherein Ais the C-Cheteroaryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed with each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Non-limiting examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group or the like. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed with each other, a heteroatom selected from B, N, O, P, Si, S, Se, and Ge, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group or the like. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

5 30 5 30 The term “C-Ccarbocyclic group” as used herein refers to a saturated or unsaturated ring group having, as a ring-forming atom, 5 to 30 carbon atoms only. The C-Ccarbocyclic group may be a monocyclic group or a polycyclic group.

1 30 1 30 The term “C-Cheterocyclic group” as used herein refers to a saturated or unsaturated ring group having, as a ring-forming atom, at least one heteroatom selected from B, N, O, Si, P, S, Se, and Ge, other than 1 to 30 carbon atoms as ring-forming atom(s). The C-Cheterocyclic group may be a monocyclic group or a polycyclic group.

5 30 1 30 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group; 1 60 2 60 2 60 1 60 1 60 5 3 2 2 3 2 2 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 11 12 13 14 15 16 17 18 19 18 19 a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, or a C-Calkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q)(Q), -Si(Q)(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof; 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group; 3 10 1 1 3 10 1 1 6 60 7 60 6 60 6 60 1 60 2 60 1 60 1 60 5 3 2 2 3 2 2 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 21 22 23 24 25 26 27 28 29 28 29 a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each substituted with deuterium, —F, —Cl, —Br, —I, —SF, —CD, —CDH, —CDH, —CF, —CFH, —CFH, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryl alkyl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryl alkyl group, a C-Cheteroaryloxy group, a C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q)(Q), —Si(Q)(Q)(Q), —B(Q)(Q), —P(Q)(Q), —P(═O)(Q)(Q), or a combination thereof; or 31 32 33 31 32 33 34 35 36 37 38 39 38 39 —Si(Q)(Q)(Q), —Ge(Q)(Q)(Q), —N(Q)(Q), —B(Q)(Q), —P(Q)(Q), or —P(═O)(Q)(Q), and 1 9 11 19 21 29 31 39 5 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 1 60 1 60 1 60 1 60 Qto Q, Qto Q, Qto Q, and Qto Qmay each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C-Calkyl group, a substituted or unsubstituted C-Calkenyl group, a substituted or unsubstituted C-Calkynyl group, a substituted or unsubstituted C-Calkoxy group, a substituted or unsubstituted C-Calkylthio group, a substituted or unsubstituted C-Ccycloalkyl group, a substituted or unsubstituted C-Cheterocycloalkyl group, a substituted or unsubstituted C-Ccycloalkenyl group, a substituted or unsubstituted C-Cheterocycloalkenyl group, a substituted or unsubstituted C-Caryl group, a substituted or unsubstituted C-Calkyl aryl group, a substituted or unsubstituted C-Caryl alkyl group, a substituted or unsubstituted C-Caryloxy group, a substituted or unsubstituted C-Carylthio group, a substituted or unsubstituted C-Cheteroaryl group, a substituted or unsubstituted C-Cheteroaryloxy group, a substituted or unsubstituted C-Cheteroarylthio group, a substituted or unsubstituted C-Cheteroaryloxy group, a substituted or unsubstituted C-Cheteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group. At least one substituent of the substituted C-Ccarbocyclic group, the substituted C-Cheterocyclic group, the substituted C-Calkyl group, the substituted C-Calkenyl group, the substituted C-Calkynyl group, the substituted C-Calkoxy group, the substituted C-Calkylthio group, the substituted C-Ccycloalkyl group, the substituted C-Cheterocycloalkyl group, the substituted C-Ccycloalkenyl group, the substituted C-Cheterocycloalkenyl group, the substituted C-Caryl group, the substituted C-Calkyl aryl group, the substituted C-Caryl alkyl group, the substituted C-Caryloxy group, the substituted C-Carylthio group, the substituted C-Cheteroaryl group, the substituted C-Calkyl heteroaryl group, the substituted C-Cheteroaryl alkyl group, the substituted C-Cheteroaryloxy group, the substituted C-Cheteroarylthio group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be:

1 9 11 19 21 29 31 39 5 1 60 2 60 2 60 1 60 1 60 3 10 1 10 3 10 1 10 6 60 7 60 7 60 6 60 6 60 1 60 2 60 2 60 1 60 1 60 1 60 3 10 6 60 For example, Qto Q, Qto Q, Qto Q, and Qto Qmay each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C-Calkyl group, a C-Calkenyl group, a C-Calkynyl group, a C-Calkoxy group, a C-Calkylthio group, a C-Ccycloalkyl group, a C-Cheterocycloalkyl group, a C-Ccycloalkenyl group, a C-Cheterocycloalkenyl group, a C-Caryl group, a C-Calkyl aryl group, a C-Caryl alkyl group, a C-Caryloxy group, a C-Carylthio group, a C-Cheteroaryl group, a C-Calkyl heteroaryl group, a C-Cheteroaryl alkyl group, a substituted or unsubstituted C-Cheteroaryloxy group, a substituted or unsubstituted C-Cheteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, a C-Calkyl group, a C-Ccycloalkyl group, a C-Caryl group, or a combination thereof.

Hereinafter, organometallic compounds represented by Formula 1 and organic light-emitting devices including the same, according to one or more embodiments, will be described in further detail with reference to Synthesis Example and Examples. However, the following examples are not intended to limit the scope of the disclosure. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of A used was identical to an amount of B used, in terms of a molar equivalent.

2-Phenylpyridine (1.75 grams (g), 11.28 millimoles (mmol)) and iridium chloride hydrate (1.89 g, 5.37 mmol) were mixed with 60 mL of 2-ethoxyethanol and 20 mL of deionized (DI) water, heated under reflux with stirring for 24 hours, and then cooled to room temperature. The resulting solid was filtered and separated, washed thoroughly with water, methanol, and n-hexane in the stated order, and the obtained solid was dried in a vacuum oven to obtain 2.33 g of Compound 1A(1) (yield: 81%).

Compound 1A(1) (2.33 g, 2.17 mmol) was mixed with 75 mL of methylene chloride, and then silver trifluoromethanesulfonate (AgOTf) (1.17 g, 4.56 mmol) mixed with 25 mL of methanol was added thereto. Afterwards, the resultant reaction solution was stirred for 18 hours at room temperature while light was blocked with aluminum foil, and then filtered through Celite to remove a solid produced therein. The solvent was removed from the filtrate under a reduced pressure to obtain a solid (Compound 1A) which was used in the next reaction without an additional purification process.

2 3 3 4 Under a nitrogen atmosphere, 2-bromo-7-oxa-1,2a-diazadibenzo[4,5:7,8]cycloocta[1,2,3-cd]indene (2.5 g, 6.88 mmol) and dibenzo[b,d]furan-4-yl boronic acid (1.75 g, 8.26 mmol) were dissolved in 120 mL of 1,4-dioxane. Potassium carbonate (KCO) (2.85 g, 20.65 mmol) dissolved in 40 mL of DI water was added to the reaction mixture, and palladium catalyst (tetrakis(triphenylphosphine)palladium(0), Pd(PPh)) (0.56 g, 0.48 mmol) was added thereto. Then, the reaction mixture was stirred and heated under reflux at 100° C. The reaction mixture was then allowed to cool to room temperature. After extraction, the obtained solid was purified by column chromatography (eluents: n-hexane and ethyl acetate) to obtain 1.92 g of Compound 1 B (yield: 62%). The obtained compound was identified by high resolution mass spectrometry (HRMS) using matrix assisted laser desorption ionization (MALDI) and HPLC analysis.

31 18 2 2 HRMS (MALDI) calculated for CHNO: m/z 450.1368; found: 450.1361.

Compound 1A (2.29 g, 3.21 mmol) and Compound 1B (1.45 g, 3.21 mmol) were mixed with 32 mL of 2-ethoxyethanol and 32 mL of N,N-dimethylformamide, heated under reflux with stirring for 24 hours, and then cooled. The solid obtained by concentrating the resulting mixture under a reduced pressure was purified by column chromatography (eluents: n-hexane and methylene chloride) to obtain 0.98 g of Compound 1 (yield: 32%). The obtained compound was identified by HRMS (MALDI) and HPLC analysis.

53 33 4 2 HRMS (MALDI) calculated for CHIrNO: m/z 950.2233; found: 950.2239.

3 5-(Methyl-d)-2-phenylpyridine (2.1 g, 12.19 mmol) and iridium chloride hydrate (2.04 g, 5.81 mmol) were mixed with 60 mL of 2-ethoxyethanol and 20 mL of DI water, heated under reflux with stirring for 24 hours, and then cooled to room temperature. The resulting solid was filtered and separated, washed thoroughly with water, methanol, and n-hexane in sequence, and the obtained solid was dried in a vacuum oven to obtain 2.58 g of Compound 18A(1) (yield: 78%).

Compound 18A(1) (2.58 g, 2.26 mmol) was mixed with 75 mL of methylene chloride, and then AgOTf (1.22 g, 4.75 mmol) mixed with 25 mL of methanol was added thereto. Afterwards, the resultant reaction solution was stirred for 18 hours at room temperature while light was blocked with aluminum foil, and then filtered through Celite to remove a solid produced therein. The solvent was removed from the filtrate under a reduced pressure to obtain a solid (Compound 18A), which was used in the next reaction without an additional purification process.

2 3 3 4 Under a nitrogen atmosphere, 2-bromo-7-oxa-1,2a-diazadibenzo[4,5:7,8]cycloocta[1,2,3-cd]indene (2.49 g, 6.86 mmol) and (7-(methyl-d3)dibenzo[b,d]furan-4-yl)boronic acid (1.88 g, 8.23 mmol) were dissolved in 120 mL of 1,4-dioxane. Potassium carbonate (KCO) (2.84 g, 20.57 mmol) dissolved in 40 mL of DI water was added to the reaction mixture, and palladium catalyst (Pd(PPh)) (0.56 g, 0.48 mmol) was added thereto. Then, the reaction mixture was heated and stirred under reflux at 100° C. The reaction contents were then allowed to cool to room temperature. After extraction, the obtained solid was purified by column chromatography (eluents: n-hexane and ethyl acetate) to obtain 1.96 g of Compound 18B (yield: 61%). The obtained compound was identified by HRMS (MALDI) and HPLC analysis.

32 17 3 2 2 HRMS (MALDI) calculated for CHDNO: m/z 467.1713; found: 467.1719.

2-Phenyl-5-(trimethylsilyl)pyridine (2.1 g, 9.24 mmol) and iridium chloride hydrate (1.55 g, 4.40 mmol) were mixed with 60 mL of 2-ethoxyethanol and 20 mL of DI water, the mixture was heated at reflux with stirring for 24 hours, and then cooled to room temperature. The resulting solid was filtered and separated, washed thoroughly with water, methanol, and n-hexane in the stated order, and the obtained solid was dried in a vacuum oven to obtain 2.18 g of Compound 40A(1) (yield: 73%).

Compound 40A(1) (2.18 g, 1.60 mmol) was mixed with 75 mL of methylene chloride, and then AgOTf (0.86 g, 3.36 mmol) mixed with 25 mL of methanol was added thereto. Afterwards, the resultant reaction solution was stirred for 18 hours at room temperature while light was blocked with aluminum foil, and filtered through Celite to remove a solid produced therein. The solvent was removed from the filtrate under a reduced pressure to obtain a solid (Compound 40A) which was used in the next reaction without an additional purification process.

2 3 3 4 Under a nitrogen atmosphere, 2-bromo-7-oxa-1,2a-diazadibenzo[4,5:7,8]cycloocta[1,2,3-cd]indene (2.49 g, 6.86 mmol) and 4,4,5,5-tetramethyl-2-(7-phenyldibenzo[b,d]furan-4-yl)-1,3,2-dioxaborolane (3.05 g, 8.23 mmol) were dissolved in 120 mL of 1,4-dioxane. Potassium carbonate (KCO) (2.84 g, 20.57 mmol) dissolved in 40 mL of DI water was added to the reaction mixture, and a palladium catalyst (Pd(PPh)) (0.56 g, 0.48 mmol) was added thereto. Then, the reaction mixture was stirred and heated under reflux at 100° C. After extraction, the obtained solid was purified by column chromatography (eluents: n-hexane and ethyl acetate) to obtain 2.31 g of Compound 40B (yield: 64%). The obtained compound was identified by HRMS (MALDI) and HPLC analysis.

37 22 2 2 HRMS (MALDI) calculated for CHNO: m/z 526.1681; found: 526.1688.

0.89 g of Compound 40 (yield: 35%) was synthesized using a similar method as the synthesis of Compound 1 in Synthesis Example 1, except that Compound 40A (1.87 g, 2.18 mmol) was used instead of Compound 1A, and Compound 40B (1.15 g, 2.18 mmol) was used instead of Compound 1B. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.

65 53 4 2 2 HRMS (MALDI) calculated for CHIrNOSi: m/z 1170.3336; found: 1170.3331.

2-Phenyl-5-(trimethylgermyl)pyridine (2.1 g, 7.72 mmol) and iridium chloride hydrate (1.30 g, 3.68 mmol) were mixed with 60 mL of 2-ethoxyethanol and 20 mL of DI water, heated at reflux with stirring for 24 hours, and then cooled to room temperature. The resulting solid was filtered and separated, washed thoroughly with water, methanol, and n-hexane in the stated order, and the obtained solid was dried in a vacuum oven to obtain 2.18 g of Compound 63A(1) (yield: 77%).

Compound 63A(1) (2.18 g, 1.42 mmol) was mixed with 75 mL of methylene chloride, and then AgOTf (0.76 g, 2.97 mmol) mixed with 25 mL of methanol was added thereto. Afterwards, the resultant reaction solution was stirred for 18 hours at room temperature while light was blocked with aluminum foil, and filtered through Celite to remove a solid produced therein. The solvent was removed from the filtrate under a reduced pressure to obtain a solid (Compound 63A), which was used in the next reaction without an additional purification process.

2 3 3 4 Under a nitrogen atmosphere, 2-bromo-5-phenyl-7-oxa-1,2a-diazadibenzo[4,5:7,8]cycloocta[1,2,3-cd]indene (2.53 g, 5.76 mmol) and 4,4,5,5-tetramethyl-2-(7-phenyldibenzo[b,d]furan-4-yl)-1,3,2-dioxaborolane (2.56 g, 6.91 mmol) were dissolved in 120 mL of 1,4-dioxane. Potassium carbonate (KCO) (2.39 g, 17.28 mmol) dissolved in 40 mL of DI water was added to the reaction mixture, and a palladium catalyst (Pd(PPh)) (0.47 g, 0.40 mmol) was added thereto. Then, the reaction mixture was stirred and heated under reflux at 100° C. After extraction, the obtained solid was purified by column chromatography (eluents: n-hexane and ethyl acetate) to obtain 2.11 g of Compound 63B (yield: 61%). The obtained compound was identified by HRMS (MALDI) and HPLC analysis.

43 26 2 2 HRMS (MALDI) calculated for CHNO: m/z 602.1994; found: 602.1999.

0.82 g of Compound 63 (yield: 32%) was synthesized using a similar method as the synthesis of Compound 1 in Synthesis Example 1, except that Compound 63A (1.82 g, 1.92 mmol) was used instead of Compound 1A, and Compound 63B (1.16 g, 1.92 mmol) was used instead of Compound 1B. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.

71 57 2 4 2 HRMS (MALDI) calculated for CHGeIrNO: m/z 1338.2534; found: 1338.2539.

A patterned indium tin oxide (ITO) glass substrate as an anode was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, ultrasonically cleaned with isopropyl alcohol and DI water for 5 minutes each, cleaned by ultraviolet (UV) irradiation and ozone exposure for 30 minutes, and installed in a vacuum deposition apparatus.

On the anode, Compound HT3 and F12-P-Dopant were vacuum-co-deposited at a weight ratio of 98:2 to form a hole injection layer having the thickness of 100 Å, and on the hole injection layer, Compound HT3 was vacuum-deposited to form a hole transport layer having the thickness of 1650 Å.

On the hole transport layer, Compound GH3 (host) and Compound 1 (dopant) were co-deposited at a weight ratio of 92:8 to form an emission layer having the thickness of 400 Å.

On the emission layer, Compound ET3 and Liq-N-Dopant were co-deposited at a volume ratio of 50:50 to form an electron transport layer having the thickness of 350 Å, and on the electron transport layer, Liq-N-Dopant was vacuum-deposited to form an electron injection layer having the thickness of 10 Å, and on the electron injection layer, Al was vacuum-deposited to form a cathode having the thickness of 1000 Å, thereby completing manufacturing of a light-emitting device.

The organic light-emitting devices were manufactured using a similar method as Example 1, except that the compounds shown in Table 1 below were used instead of Compound 1 during the formation of the emission layer.

97 97 For the organic light-emitting devices of Examples 1 to 4 and Comparative Examples 1 to 3, the driving voltage (Volts, V), the maximum external quantum efficiency (Max EQE, %), the maximum emission wavelength (nm), the roll-off ratio (%), and the lifespan (LT, relative %) were evaluated, and the results are shown in Table 1 below. As evaluation apparatuses, a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used. The roll-off ratio was calculated according to Equation 1 below, and the lifespan (LT), measured as the time required for the luminance to reach 97% of 100% of the initial luminance at 6000 nits, is shown relative to Comparative Example 1.

TABLE 1 Dopant compound Maximum in Driving Max emission Roll-off emission voltage EQE wavelength ratio Lifespan layer (V) (%) (nm) (%) (%) Example 1  1 4.5 25 525 13 140 Example 2 18 4.4 26 526 11 160 Example 3 40 4.3 27 532 10 180 Example 4 63 4.3 27 531 10 170 Comparative CE1 4.9 22 524 15 100 Example 1 Comparative CE2 5 22 522 16  90 Example 2 Comparative CE3 4.9 23 525 15  20 Example 3 1 18 40 63 CE1 CE2 CE3

From Table 1, it was confirmed that the organic light-emitting devices of Examples 1 to 4 have characteristics of low driving voltage, high maximum external quantum efficiency, reduced roll-off ratios, and long lifespan.

Further, it was confirmed that the organic light-emitting devices of Examples 1 to 4 exhibit a lower driving voltage, a higher maximum external quantum efficiency, a smaller roll-off ratio, and a longer lifespan compared to the organic light-emitting devices of Comparative Examples 1 to 3.

Because the organometallic compound represented by Formula 1 has excellent electrical characteristics, an electronic device using the at least one of the organometallic compounds represented by Formula 1, for example, an organic light-emitting device using the organometallic compound represented by Formula 1 may have characteristics of a low driving voltage, a high maximum external quantum efficiency, a low roll-off ratio, and a long lifespan. Therefore, a high-quality organic light-emitting device can be realized using at least one of the organometallic compounds represented by Formula 1.

It should be understood that exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more exemplary embodiments have been described with reference to the FIGURE, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.